The present invention relates to an alternative cover for landfills, and more particularly, is directed to an alternative daily cover for landfills using recycled materials which meets the Department of Environmental Protection requirements for a daily cover and inhibits the release of hydrogen sulfide gas therefrom.
State and federal environmental regulations generally require operators of landfills to periodically cover exposed solid waste, typically at the end of each working day or at the end of every 24 hours. The daily cover is used to prevent vectors, odors, blowing, litter and other nuisances from the landfill and is also required to prevent fires and to allow loaded vehicles to successfully maneuver on landfill after the cover material has been placed. Generally, the layer of cover material is required to be a minimum of 6 inches thick and a supply of the cover must be maintained on site and may be left in place for up to seven days. An intermediate cover is necessary for longer durations and must be a minimum of 12 inches thick. Materials used for intermediate covers must be capable of sustaining vegetation in some states, at least temporarily, prior to receiving a final cover in order to protect against corrosion and sedimentation. The daily cover requirements vary somewhat from state to state, but the material used is generally known in the industry as “daily cover”, or “periodic cover” when the interval is more than one day (for example two or three days). As used herein “daily cover” is intended to include both daily and periodic cover for landfills such as municipal solid waste (MSW) landfills, rubble landfills, land clearing debris landfills, and industrial waste landfills.
A significant constituent of many landfills is construction and demolition debris may include percentages of sulfate containing material. Under the anaerobic conditions in the typical landfill, sulfate-reducing bacteria produce hydrogen sulfide (H2S) from the sulfate containing materials and the organic carbon in other waste material within the landfill. While daily cover is effective at containing debris and the like within the landfill, it is ineffective for trapping or containing the biogas within the landfill. Additionally, some alternative cover materials may comprise significant quantities of construction and demolition debris containing concentrations of sulfate containing materials which further promotes the formation of hydrogen sulfide gas. Hydrogen sulfide gas escaping from the landfill creates an offensive odor for people near the landfill as well as nearby neighbors. Consequently, public opposition to landfills by proximate property owners is generally high due to the expected odor problems, among other concerns. It would also be desirable to provide an alternate intermediate cover that could absorb or otherwise contain the hydrogen sulfide gas thereby reducing or eliminating the odor problem. It would also be advantageous is the absorbing alternate intermediate cover could continue to be produced using primarily recycled materials.